http://cgit.freedesktop.org/zeitgeist/zeitgeist/commit/?id=3fe95cdb5a4c48d3b6606ffb1f60fae3e375fdff

--- ./libzeitgeist/log.vala.orig	2013-06-17 06:40:08.000000000 +0000
+++ ./libzeitgeist/log.vala	2014-05-29 17:19:07.000000000 +0000
@@ -58,8 +58,8 @@
  */
 public class Log : QueuedProxyWrapper
 {
-    [CCode (cheader_filename = "sys/sysinfo.h", cname = "get_nprocs_conf")]
-    extern static int get_nprocs_conf ();
+    [CCode (cname = "g_get_num_processors")]
+    private extern static uint get_num_processors ();
 
     class DbWorker
     {
@@ -141,7 +141,7 @@
         try {
             threads = new ThreadPool<DbWorker>.with_owned_data ((worker) => {
                 worker.run ();
-            }, get_nprocs_conf (), true);
+            }, (int) get_num_processors (), true);
         } catch (ThreadError err) {
             warning ("%s", err.message);
             threads = null;
